“Hydrosols are the condensate water co-produced during the steam or hydro-distillation of plant material for therapeutic purposes.” - Suzanne Catty
As far back as the 11th century, plant material was distilled expressly for the hydrosols it produced; essential oils were considered the by-product and often tossed aside. Hydrosols were most in use during the 18th century, in Europe. Due to the high volume of hydrosol that can be produced through distillation, new uses for the essential oils were researched, so distillation could be commercially viable. As more and more research was conducted, so did essential oils become more valuable. Today, essential oils are much more common therapeutically than hydrosols, but many feel that hydrosols are an invaluable tool to practical applications in daily life.
Hydrosols are sometimes referred to as floral waters, distillates or hydrolats. Many products on the market are merely water, essential oil and an emulsifier. Some hydrosols have the additions of vegetable glycerin, PEG-40 hydrogenated castor oil, potassium sorbate, citric acid and dimethicone defoamer. Even in trace amounts, we consider these additions adulterations. These adulterations are not always displayed on the label. If you are planning to use hydrosols as therapeutic healing agents, you must demand pure, fresh, clean product free of anything other than the distillate water.
Hydrosols could be seen as the homeopathic sibling of the essential oil. Just as a homeopathic remedy contains a minute amount of the original material from which it is made, a hydrosol contains tiny amounts of the water soluble material from which it is made.